Television motor structure



J 2, 19351 -G. v. VQDILLENBACK, JR 2,006,796

v TEEEVISION'MOTOR STRUCTURE Filed May 20, 1930 2 sheets-sheet 1 INVENTOR krronus'vi damusrr VDAZLE/VJACK JR.

July 2, 7

Filed May 20, 1950 128 /IIlIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII/III evv. v. DILLENBACK, JR TELEVISION MQTQR STRUCTURE" 2 Sheets-Sheet 2 GARKHT vane/mar JR- INVENTOR ATTORNEY Patented July 2, 1935 v TELEVISION MQTOR STRUCTURE Garrett Vander Veer Dillenback, Jr., Slingerlands, N. Y., a.ssignor, by mesne assignments, to Radio Corporation of America, a corporation of Delaware Application May 20, 1930. Serial No. 453,890

10 Claims. (Cl.17869.5)

This invention relates to motor devices and rents, to control the synchronous speed of the mowith particularity to a novel type of motor suittor. able for use in electro-optical systems such as A further feature relates to an eddy-current television, picture transmission, etc. motor of the rotating disc type wherein the disc is In certain of the signaling arts, for example coupled to a member which controls the syn- 5 television, photo-telegraphy, etc., it. is required to chronous speed of the disc. operatereceiving apparatus with a high degree A still further feature relates to a televisionof accuracy as regards synchronism with the or facsimile system wherein the receiving mechtransmitting apparatus. Particularly in the art anism is operated by a novel eddy-current motor of television is such accuracy of synchronism a which derives its power from the image or picture 10 pro-requisite to faithful reproduction of visual currents sent from a transmitting station, thus representations, since there must be both synavoiding the use of a separate synchronizing chronism and isochronism between the transmitchannel. .ter and receiver. Furthermore, it is a pre- Other features and advantages not specifically requisite in such systems to provide a driving enumerated will be apparent after a considera- 15, mechanism for the signal transmitter and re tion of the following descriptions and the approducer which responds with the utmost rapidipended claims. ty to correcting impulses in the event that the In achieving the above and other advantages it transmitter and reproducer tend to fall out of is D DO to employ device Whith combines step. the functions of-a synchronous motor and an 20 Accordingly it is one of the principal objects eddy-current motor. One of the inductors for of the present invention to provide a novel motive th ed ymotor is u d as the ia of source for driving signal transmitting and/or the SynchrOnOus motor. reproducing devices. The rotor of the synchronous motor may be Another object is to provide a method of drivof t u ua f m co s o a toothed .disc 25 ing Signal transmitters and/or reproducers of. solid or laminated iron or other paramagnetic whereby the mechanisms may be corrected or materialwhich may 0 y not b Wound a ay synchronized within a minimum time int rval. or may not have a direct current field. If a field While it has been proposed heretofore to synis employed this may be supplied by passing direct chronize receiving mechanism by synchronizing current through windings on the stator or rotor 30 signals from the transmitting station these prior by using a p ra e ta y fi d Winding art methods have required relatively complex apor y p a ly ma i the rotor 0 stat paratus which requires careful adjustment for The d ynt motor is a y placing the proper operation, 1 I conducting disc in a rotating magnetic field. It is therefore another object of this invention Th r tati fi ld i t pr du d by p a 35 to provide a synchronizing method particularly two Wound 00185 with their ends 116a! o t well suited t television systems, which method and n ar h dis s that a v yin flu inthe requires relatively inexpensive and simple apcores will produce y Currents in the disc, the paratus. Accordingly the frequency components rr n s pposite one core being disp ac from 4 inherent in the image currents, and bearlngadefth s pp s t the th mechanically, in the inite relation to the speed of the transmitter, may d s ed d ect o of rotationhe flux in one be used for synchronizing. core is made out of phase with the flux in the Another object of the invention is to provide a h r core- Th s may be d y p ratin h novel type of synchronous motor which is of sim- COilS different Phases of a Polyphase pp y ple construction, possesses a light movable mem- 01 by tu n One Coil with a condenser y 9- 45 her or rotor whereby its synchronous speed may ra in n c il in s ries wi a l r nd nser corrected ith a maximum rapidity. or by operating one coil with high inductance A feature of the invention relates to a motor as Primary Of a transformer a d he ot er with of the induction type wherein the field magnet 10w induc nc a c n ry r y ny' f th '50 is employed for the double purpose of induction ev al e k w methOdS- Both 00.118 may b and synchronizing. arranged on the same core or several cores may Y Another-feature resides in a synchronous motor be used, on opposite sides or on "the same side of the eddy-current type having a toothed or salof the disc. The toothed synchronizing disc is lent pole member which is adapted to be aflected so located that it is acted upon by the flux'from by'the same field which creates the eddy-curone of the eddy-current motor inductors. It may 55 I By using one toothed disc on one inductor and.

be placed between two legs of one of the cores or near one of the legs. It may be used with any of the inductors.

The apparatus is economical to manufacture, can be easily changed from one synchronous speed to another by changing toothed discs and may be operated at speeds other than synchronous by adjusting the speed control. A separate synchronous motor may be attached for using picture or synchronizing signals for synchronizing. There are no moving contacts to cause trouble or noise.

a different disc on another or the same inductor the motor may be made to synchronize on either of two speeds by adjusting the speed control.

Referring to the drawings: v Figure 1 shows a front view of a television receiving device embodying principles of the invention; i

Fig. 2 is another view of the device of Fig. 1

'showing more clearly the relations of the disc vand driving magnets; this figure also shows schematically a television transmitter in conjunction with the receiving, device;

Fig. 3 is another view of part ofthe device of Figs. 1 and 2;

' Fig. 4 shows a modified embodiment of the invention;

Fig. 5 shows a modified manner of arranging the synchronizing rotors;

therein. Disc I is attached to a shaft 2 which is mounted in suitable bearings (not shown). Fastened to disc I in any suitable manner is a toothed member I of paramagnetic material.

The teeth are designed to fimction as salient poles and their number depends upon the speed atwhichthedisc I istobedrivenaswillappear hereinafter. Mounted in close proximity to one face of the disc on any suitable support (not shown) and in cooperative relation with the poles of member 3, is an electro-magnet 4 comprising the U-shaped core, preferably of laminated iron. Magnet 4 is provided with a suitable field wiring 5 adapted to be energizedby the synchronizing currents from source I. Source 8 may take the form of a lcommercial alternating current supply main, or any other network common to both the transmitter and receiver. Mounted in close proximity to the opposite face of disc I is another electro-magnet 'I having preferably, al-

thoughnot necessarily, an E-shaped laminated core and a field winding I. The winding I is connected to the source I and in series with the winding 5 through a condenser I whereby the currents flowing through the windings are displaced in, phase. By well known principles, there will be eddy-currents produced in disc I due to both magnet I and magnet I. Since the effects of these magnets are out of phase there is produced a torque on the disc I which therefore tends to rotate. It will be understood, of course, that instead of employing a condenser to displace the phase of the fields of the magnets any other manner of effecting this phase displacement may be employed.

While the disc I may be driven through guitin brilliancy in accordance with the image currents received over line or channel I2. If the scanning elements are arranged in,a plurality of convolutions, then a light source and switching arrangement of the type disclosed in United States Patent.#1,683,137 to C. FQJenkins, may be employed.

" In order to expedite framing" the lamp II may be provided with a slidable cover It having anaperture H. The cover'm'ay be moved to expose the desired set of spiral perforations in the disc through the aperture II.

Inasmuch as'the poles or teeth of member 3 are within the influence. of magnet 4, for each cycle of the alternating current applied to windings 5 and 8 there will be an impulse delivered to the member 3 and consequently to disc I. The magnitude of this impulse will of course depend upon the relative phase displacement between the fields due to the magnets and the center line of each of the poles; consequently the member 3 will tend to run in perfect step with the frequency of the currents applied to the windings.

' However, the main driving power for disc I is derived from the action of the eddy-currents and the function of the device 3 coacting with magnets is merely to insure accurate synchronism with the supply.

It has been found that in these scanning methods there is inherent in the image currents themselves a frequency component which bears a'deflnite relation to the speed of the transmitting scanner. For example, if an image is scanned by a disc scanner having 48 scanning elements eflective per second, the image currents will have a corresponding characteristic frequency component. Similarly if the object being scanned is a. motion picture film wherein frames are scanned per second there will be in the image currents a characteristic component having a frequency of 15 cycles per second,-as set forth .in the copending application of C. E. Huifman, Serial No. 365,818. The image currents arriving at the receiving station after being demodulated and amplified may be applied to the reproducing lamp I I and also to the windings 5 and 8. v

Instead of applying the image currents with the characteristic inherent frequency to the magnets 5 and 8 these currents after suitable ampli fication may be used to operate a synchronous motor which is separate from the structure disclosed in the drawings but is coupled to the disc shaft 2 in any suitable manner, in which case the disc proper may be driven by induced eddycurrents derived from a local source of current. In other words the image currents serve to keep the disc in step while the eddy-currents serve as the main driving means for the disc proper.

While the synchronizing rotor member 3 as disclosed in Fig. 3 may be of permanently magnetized iron, it may be desired to employ electro-magnetic excitation. Thus as shown in Fig. 4 the disc I is driven by induced eddy-ycurrents from the main magn t I5. The core of magnet I5 may be provided wit inwardly extending'pole portions I6, I 1, which cooperate with the armature l8 ailixedto shaft 2. Armature it may be of any well known construction as ordinarily employed in synchronous motors, and is energized by suitable windings I3 that are connected through brushes 2| to a source of constant current. The synchronizing currents for driving the disc i are applied to the main windings 22 causing the disc I to rotate, but the speed of rotation is controlled by the poles I6, I! and the armature l8.

While two methods of using the main :lield winding to control the synchronous rotation of the disc are specifically disclosed it will be understood that the invention is not limited thereto. Thus instead of employing a toothed disc 3 as the synchronizing rotor in Figs. 1 and 2, the separate magnetic poles may be provided and attached to the disc. I

Referring toFig. 5, there is shown another modification of the invention wherein the disc 23 carries a pair of synchronizing rotors 24 and 25 on opposite sides thereof. Rotor 24 has a different number of teeth or polar projections from the member 25 in order that the disc 23 may be synchronously driven at correspondingly difierent speeds. Thus the member 24 may be designed to synchronize the disc 23 at 900 R. P. M. when a certain frequency of current is applied to the coils 26 and 21. While the member 25 may be designed to synchronize the disc 23 at a speed of 1200 R. P. M., for example, it will be obvious of course that the members 24 and 25 may be repiaceably attached to the disc 23 in order to synchronize the said disc at any other speed, it being understood of course that a corresponding synchronizing member is used for such desired speed. In the embodiment of Fig. 5 it will be understood that the frequency of the alternating current applied to the members 26 and 21 will correspond to the particular one of the members 24 or 25 .which it is desired be effective in synchronizing.

It will also be understood that the members 24 and 25 are effective to produce their synchronizing action only when, currents of the associated proper frequencies (or other frequencies within narrow limits) are applied to the inductors.

Referring to Figs. Sand 7 there is shown in detail one preferred manner of supporting and arranging the elements of a completetelevisor embodying features of the invention. In this figure thelnumeral 28 represents a supporting base of any suitable material having a pair of uprights 29 and 30 either attached thereto or formed integrally therewith as a single casting. The upright 29 has fastened thereto by suitable bolts 30 a U-shaped laminated magnet 3| provided with a pair of windings 32. Similarly at,- tached -to opposite sides of the upright 30 are two U-shaped magnets 33 and 34 provided with respective windings. 35, 36. Mounted for rotation in the upright 30 is a shaft 31 which is preferably provided with anti-friction bearings in said uprights. Shaft 3'I carries at its left hand endthe scanning disc 38 and also the synchronizing rotor 39. As shown more clearly in Fig. '7 the rotor 33 is disposed between the opposite legs of the magnet 3! so as to be within the influence of the,

magnetic field therefrom. The upright 29 carries a bracket 40 toreceive a plunger like extension 4| attached to a lamp socket or base 42 of insulating material. The plunger support 4i preferably is supported frictionally inthe bracket 43 so that the base 42 may be raised and lowered to properly frame the picture vertically.

Due to this method of supporting, the base also be rotated to frame the picture horizontally. The base 42 is provided with suitable contact sockets to receive the contact prongs 43 of'the glow lamp 44 which may be of the gaseous discharge type such as a neon lamp having a flat plate electrode '45. The upright 30 terminates at its upper end in a ring shaped portion 44 rounded by an opaque housing 50 which may be fastened to the base 42 by screws. Housing ill is provided with the proper size of opening it to illuminate the scanning field traversed by the scanning apertures in the disc 38 in the well known manner. A suitable switch (not shown) for controlling the application of current to the magnet windings may be mounted on the front portion of the base 28 and a suitable rheostat (not shown) may also be mounted on the base to control the non-synchronous speed of the disc 38. The edge of disc 38 is protected by means of a flat ringof metal 52 which is fastened at its lower ends to the base 28 and is supported at its upper end by means of a metal strip 53 attached by screw 54 to the upper portion 46 of the upright 30.

It is believed that the operation of the mechanism disclosed in Figs. 6 and '7 will be understood when considered in connection with the description hereinabove given in connection with Figs. 1 to 5. I

Furthermore, while the invention is shown as embodied in a television system, it will be understood that the broad concept of the invention wherein the same field acts as a ,motive source and as a synchronizing source is capable of embodiment in other arrangements which will be apparent to those familiar with the art.

The apparatus disclosed herein is relatively economical of manufacture andenables a machine to be readily changed from one synchronous speed to another, merely by substituting the proper toothed discs or synchronizing members, and furthermore the device may be operated at speeds other than synchronous speeds by merely adjust-- ing the speed control. This necessarily follows because the members 24 and 25 attain their true synchronizing eifect when their rotation is in step with the frequency of the supply.

What is claimed is:

l. A television device comprising a scanning disc, 'means for producing a magnetic field for driving said disc by eddyecurrent action on said disc and a synchronizing device controlled by said field. 2. A television device comprising a scanning disc serving as the rotor of an eddy-current motor, means for'producing a magnetic field for chronizing means comprising a plurality of magnetic poles adapted to be acted upon by the disc driving means. I

4.. Ina television machine the combination of a support, a television scanning device mounted for rotation on said support, a pair of electro-mag-.

nets mounted adjacent opposite faces of said device; a synchronizing rotor coupled to said device and mounted to be within the fleld produced by one of said magnets, and means for producing displaced magnetic ilelds from said magnets.

5. In a television machine the combination of a television scanning device, means for producing displaced magnetic fields to drive said device asynchronously by eddy current induced therein, means for varying the asynchronous speed, and means including the first mentioned means and a synchronizing member for causing said device to rotate at synchronous speed.

6. In a television machine the combination of a rotatable television scanner device, a pair of electromagnets mounted adjacent one face of said device, and another electromagnet mounted ad- Jacent the opposite face of said device, all of said electromagnets exerting an eddy current action on said scanner, and means for applying phase displaced currents to said pair of magnets and to saidother magnet.

'1. In combination a television scanning disc, a salient pole magnetic member coupled to the disc shaft, a pair of electro-magnets facing said disc for driving the same by inducing eddy currents therein, means for displacing the phase of the currents applied to said magnets, at least one of said magnets having its poles adjacent to said i magnetic member.

8. In combination a rotatable television scanning device, a pair of .electro-magnets mounted adjacent opposite faces of said scanner for inducing eddy currents therein, andmeans i'or apto drive said device by inducing eddy currents in said device.

'9. In combination a television scanning disc, a pair of salient pole magnetic members coupled plying phase displaced currents to said magnets to the disc shaft, a pair of electro-magnets facing said disc for driving the same by inducing eddy GARRE'I'I VANDER VEER DILLENBACK, J Ii. 

